In some bios settings you have the option to turn on and off cores. Check to see if all the cores are turned on. The only reason I say this is my asus bios gives me the option to enable or disable cores. For some reason they could be turned off. Its worth a check.

If the pins ever bend on a CPU you can always use a small mechanical pencil or pen to straiten them. I have successfully done this on an Athlon 2. I would definitely update your bios or attempt to, because if you have an older base chipset more modern CPU's may not work in them.

If the pins ever bend on a CPU you can always use a small mechanical pencil or pen to straiten them. I have successfully done this on an Athlon 2. I would definitely update your bios or attempt to, because if you have an older base chipset more modern CPU's may not work in them.

Here's something that could be the reason...

When I turned on the PC the first time after assembling, the older installation of XP wouldn't boot. As soon as the Windows XP logo appeared, the computer shut down.

I thought it could be something related to power options, so I went to the BIOS and disabled ACPI APIC Support. Then restarted the computer and the OS still didn't boot, but at least it didn't shut down my computer either.

It was after that that I made a clean installation of XP from scratch.

But now I've read in several ACPI-related articles, that with APIC disabled, only one core is active. So that's the reason why my CPU is slow and why CPU-Z shows only one core.

Tomorrow I'll try enabling APIC again. If it still shuts down like it did yesterday, I'll let you know.